Abrading machine



June 25, 1968 M. w. BRODIGAN ABRADING MACHINE Filed Dec 20, 1965 2 Sheets-Sheet l INVENTOR. Ml HAEL Vi BR DIGAN IZA AGENT June 25, 1968 M. w. BRODIGAN 3,389,509

ABRAD ING MACHINE Filed Dec. 20, 1965 2 Sheets-Sheet 2 INVENTOR. 7 MICHAEL H BRODI J BY AGENT United States Patent 3,389,509 ABRADING MACHINE Michael W. Brodigan, 416 Fillmore St., Cottage Grove, Oreg. 97424 Filed Dec. 20, 1965, Ser. No. 515,135 Claims. (Cl. 51-176) This invention relates generally to abrading machines and more particularly to a hand tool including a resiliently mounted housing in which is removably journalled an expandible abrading drum assembly.

An important object of this invention is the provision of means supporting the drum assembly within the housing which permits quick detachment of said assembly for replacement of disposable abrading sleeves. In this regard, cooperating end plates engage the end walls of the drum with one of said end plates being axially positionable into and out of engagement therewith to permit easy removal and re-installation of the drum within the housing. Presently the replacement of drum mounted abrading components of similar machines constitutes a task requiring a period of minutes which, over an extended period, amounts to considerable non-productive time.

A further object of the present invention is to provide an expandible core of simple, unitary construction which upon detachment from the abrading machine may be conveniently reduced in diameter without the use of accessory tools hence facilitating the efficient replacement of a new abrading sleeve.

Another object is the provision of resilient support means carried by guides or runners and supporting the housing in a manner allowing the abrading cylinder within the housing to bear upon the work surface in various selected degrees of pressured contact. Associated with i this feature is the effective operation of the abrading drum assembly on surfaces too rough or irregular to be sanded by conventional abrading devices. The resilient support means provided allows the abrading of extremely irregular surfaces for the reason that the work engaging guides are laterally disposed from the rectilinear path of the abrading cylinder.

The foregoing and other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof and in which:

FIGURE 1 is a perspective view of the present invention.

FIGURE 2 is a side elevational view thereof with fragments broken away for illustrative purposes.

FIGURE 2A is a fragmentary view of one end of a runner with a crosspiece attached intermediate the runner ends.

FIGURE 3 is a plan view of FIGURE 2 with the runners removed and parts broken away from the housing for purposes of illustration.

FIGURE 4 is a view taken along line 4-4 of FIGURE 3 showing the abrading drum assembly in fragmentary form and supporting end plates also with fragments broken away.

FIGURE 5 is an end view of the abrading drum assembly taken approximately along line 5-5 of FIG- URE 4.

FIGURE 6 is a fragmentary, side elevational view of the core of the expansible abrading drum assembly in a contracted position, and shown in broken lines in the expanded position.

FIGURE 7 is a fragmentary view of modified means for locking the core of the drum assembly in the expanded position.

FIGURE 8 is an end view of FIGURE 7 on a reduced sca e.

3,389,509 Patented June 25, 1968 With continuing reference to the drawings and particularly FIGURES 1 and 2 thereof, the numeral 1 indicates generally a rectangular housing compartmented into a drum section 2 and a closed motor section 3 by a transverse inner wall 4. An electric motor M is suitably mounted on the wall 4 and is provided with switch control means, not shown. A closure plate 1A removably attached to the bottom of the motor section 3 completes the enclosure of the motor M. Handles are indicated at H.

The rectangular housing 1 is yieldingly supported by resilient mounting means in the form of collars S mounted as at 6 on the housing adjacent each of its four corners. Runners 7 laterally spaced from the housing are provided with posts 8 which function as guides for springs 9, the latter supporting the weight of housing 1. The upward biasing of the collars 5 against their respective heads 8A formed on the posts 8 positions the housing in raised relationship to a work surface S. The collars 5 are formed internally as at 5A to prevent binding with the posts upon asymmetrical downward movement of the housing relative to the runners 7. FIGURE 2A shows in fragmentary form the forward end of a runner provided with crosspiece 7A attached at its opposite end to the forward end of the other runner. By providing the fore and aft ends of the runners 7 with crosspieces 7A the instant device may be used on work surfaces having a width less than the distance between the runners 7.

Transversely positioned within section 2 of the housing is the abrading drum assembly indicated generally at 10 provided with a removable abrading sleeve 11 which may be of sandpaper or other suitable abrading material.

The drum assembly 10, as best seen in FIGURE 4, is rotatably supported at its ends by a pair of cooperating axially aligned end plates 12 and 13 having inwardly extending projections 12A-13A respectively, engageable with the corresponding ends of the drum assembly 10. End plate 12 is integral with a pulley member 14 both of which are concentric with the axis of a shaft 15 journalled within a housing mounted bearing 16. A V-belt 17 permanently entrained over pulley 14 and a motor pulley driving the drum assembly 10 through an opening 4A in the Wall 4.

The opposite end of the drum assembly is supported by a housing mounted bearing indicated at 19 in which a shaft 20 is journalled, the latter being axially bored at 20A (FIGURE 4) to receive both the end of a stub shaft 21 formed on end plate 13 and a spring member 22.

The end plate 13 is disengaged from the drum assembly by means of a finger pull in the form of a crosswise pin 23 carried by the shaft 21. The pin 23 moves within a pair of opposed, elongated openings 2013 in the shaft 20.

The abrading drum assembly 10 is best shown in FIG- URES 4 and 5 and comprises a drum 25 of suitable flexible material having a normal outer diameter slightly less than that of the abrading sleeve 11. End walls 26 and 27 of the drum 25 are provided with circumferentially spaced recesses as at 26A and 27A for the reception of projections 12A and 13A respectively. Internally of the drum 25 is a two-piece hollow, cylindrical core comprising a pair of matching members 28-29 each being substantially semicircular in section. Members 28-29 comprising the core of the drum assembly are interconnected by a plurality of toggle links 30 to a centrally disposed bar 32. Toggle links 30 are pivotally attached by transverse pins 31 at their outer ends to members 28-29 and similarly at their inner ends to bar 32 by pins 33. It will be noted in FIGURE 5 that the ends of pins 31 are formed to lie flush with the outer periphery of the members 28-29. The bar 32 is provided with openings 32A in its upper and lower sides to receive the inner ends of the toggle links 30, and are so formed to limit the arcuate movement of the links from an over-center upright locking position to the inclined position of FIGURE 6. The members 28-29 are provided with flanges 28A and 29A at both of their ends and which bear against the end walls 2627 of the drum. The end plates 12-13 are relieved as at 12B and 13B to receive the flanges 28A and 29A. An over-center lock is formed by the toggle links 30 bearing upon the upright wall indicated at 328 of the opening 32A.

A modified form of locking means is shown in FIG- URES 7 and 8 wherein a bar 35 within a core formed by matching members 35 and 37 is secured relative the expanded members by a spring biased lock carried at one end of the bar and thus obviating the over-center positioning of toggle links 38. The lock includes a pair of upright plates 39 each having a finger tab 4% punched outwardly therefrom. The plates 3% are radially urged by a coil spring 41 into insertion at their outer ends within slots 42 formed in the members 36 and 37, The bar 35 is bored at 43 to receive the spring 41 along with the bifurcated, inner ends of the plates 39 which bear upon opposite ends of the spring and which slide within diametrically opposed grooves 44.

In the following operation only the replacement of an abrading sleeve 11 is described since the manner in which the drum assembly is applied to the work surface is believed obvious. As viewed in FIGURE 3, the pin 23 constituting a finger pull is positioned outwardly toward the wall of housing 1 resulting in stub shaft 21 partially compressing spring 22. End plate 13 along with the projections 13A thereon are removed from the corresponding end of the drum assembly a distance suflicient to permit the drum assembly to be disengaged from the opposite end of plate 12 and its projections 12A.

Upon removal of the drum assembly 10 from the housing bar 32 therein is manually positioned to the right relative to members 28-29 as shown in FIGURE 6 contracting the members and relaxing the circumposed drum of the core. The over-center locked position of the toggle links is overcome by such positioning of the bar 32 causing slight outward movement of the members 28 and 29 permitting the links to swing to the inclined position shown in FIGURE 6. The used abrading sleeve 11 is removed from the relaxed drum 25 with subsequent replacement of a new sleeve. The core of the drum assembly defined by members 2829 is of a diameter sufiicient to permit the manual positioning of bar 32 axially therewithin. The replacement of a new abrading sleeve 11 and locking of the toggle links 30 by movement of bar 32 to the left from its position as viewed in FIGURE 6 circumferentially expands the drum against the sleeve securing the latter thereto.

The foregoing operative description applies to the modified core shown in FIGURES 7 and 8 with the only difference lying in the locking means provided which allows positioning of the bar without necessitating the toggle links 38 to pass through a dead center position.

While I have shown particular forms of embodiment of my invention, I am aware that many minor changes therein will readily suggest themselves to others skilled in the art without departing from the spirit and scope of the invention.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. An abrading machine comprising:

a housing having a motor mounted therein,

support means for said housing engageable with a work surface,

a drum assembly comprising a flexible drum and including expandable means carried within and engageable along the inner periphery of said drum for the circumferential expansion of said drum for engagement with a circumposed abrading sleeve,

a pair of cooperating end plates rotatably mounted within said housing and engageable with said drum at the ends thereof separate of and spaced from said expandable means, one of said end plates in driven engagement with said motor, and

spring biased means bearing upon at least one of said end plates urging the latter into drum engagement.

2. An abrading machine as claimed in claim 1 wherein said support means includes a pair of runners each laterally and downwardly disposed from said housing and carrying resilient members biasing said housing upwardly away from the work surface and whereupon downwardly exerted pressure on said housing against said resilient members will operatively bring said drum assembly into contact with the work surface.

3. An abrading machine as claimed in claim 1 wherein said means for the circumferential expansion of said drum includes arcuate members and an axially positionable bar axially disposed within said members and said drum and toggle link coupling said bar and said members whereby positioning of the bar in one direction relative to the members will cause movement thereof in an outward direction while axially positioning of the bar in an opposite direction will cause said members to move inward permitting said flexible drum to contract away from the abrading sleeve.

4. The abrading machine as claimed in claim 3 wherein said bar includes locking means carried at one end thereof and outwardly biased into locking engagement with said drum assembly members whereby the toggle links carried by said bar are maintained in an upright position expanding said arcuate members and said flexible drum.

5. An abrading machine as claimed in claim 1 wherein said drum assembly comprises a drum of expandible material having circumferentially spaced recesses formed in the ends thereof, a pair of members engageable with the inner periphery of said drum and extending the length thereof terminating in outwardly extending flanges, a bar axially disposed Within said drum and said members and having openings formed therein, toggle links coupling said bar to said members and pivotally connected at their outer ends to said members and similarly connected at their inner ends to said bar within said openings and cooperating with the latter to form an over-center lock, and said end plates include projections positionable into and out of said recesses.

References Cited UNITED STATES PATENTS 1,337,017 4/1920 Kenworthy 242-72 1,404,342 1/1922 Clarke. 1,641,984 9/1927 Miller. 2,020,157 11/1935 Myers 51-176 2,069,700 2/1937 Emmons. 2,083,793 6/1937 Price 5l176 X OTHELL M. SIMPSON, Primary Examiner. 

1. AN ABRADING MACHINE COMPRISING: A HOUSING HAVING A MOTOR MOUNTED THEREIN, SUPPORT MEANS FOR SAID HOUSING ENGAGEABLE WITH A WORK SURFACE, A DRUM ASSEMBLY COMPRISING A FLEXIBLE DRUM AND INCLUDING EXPANDABLE MEANS CARRIED WITHIN AND ENGAGEABLE ALONG THE INNER PERIPHERY OF SAID DRUM FOR THE CIRCUMFERENTIAL EXPANSION OF SAID DRUM FOR ENGAGEMENT WITH A CIRCUMPOSED ABRADING SLEEVE, 